Presser-foot for skiving-machines



W. P. CROCKETT.

PRESSER FOOT FOR SKIVING MACHINES.

APPLICATION FILED JULY 9, 1918.

1,372,643 Patented Mar. 22, 1921.

WITNESS I INVENTOR a; difif WiZZmrzzfUmfiezj BY WW ATTORNEY "Anal a. rib

a t l i L mit WILLIAM P. CROCKETT, 0E BRIDGEPORT, CONNECTICUT, ASSIGNQB TO THE SINGER I/IANUFACTURING COMPANY, A GORTBORATION OF NEW JERSEY.

PRESSER-FOOT FOR SKIVING-MACHINES.

Specification of Letters Patent.

Patented Mar. 22, 19231.

T 0 (all whom it may concern:

Be it known that I, VVTILLIAM P. CRooKn'rT, a citizen of the United States, residing at Bridgeport, in the county of Fairfield and State of Connecticut, have invented certain new and useful Improvements in Presser- Feet for Skiving-Machines, of which the following is a specification, reference being had therein to the accompanying drawings.

This invention relates to skiving machines adapted to skive or scarf materials either by splitting the same or by beveling the edges thereof, and more particularly to improvements in presser-feet for skiving machines as disclosed in my cope-nding patent application Serial No. 133,853, filed November 28, 1916.

Skiving machine presser-feet, as usually constructed, include a work-engaging surface that is curved substantially in conformity with the curvature of the feed-wheel of the machine. When altering the angle of the skiving, it has been a common practice to suitably adjust the angular position of the presser-foot with relation to the skiving knife. In adjusting the presser-foot'for this purpose it is desirable to alter, by a single adjustment, the angle of skiving without changing the existing thickness of the edge of the skiving and to retain as nearly as possible the relative lateral position of the prcsser-foot and feed-wheel. To this end the presser-foot described in my prior application referred to was mounted to swing about an imaginary axis coinciding with one of the lateral edges determining the length of the work-engaging surface of the presser-foot. It is found in practice, however, that the lost motion incident to this form of construction is sufficient to at times destroy the accuracy of the adjust ment.

The primary object of this invention is to avoid all possibilities of obtaining inaccurate adjustments and to retain nevertheless the advantages of my prior presser-foot.

In accordance with the preferred embodiment of the present construction the presserfoot is mounted for oscillatory adjustable movement upon a pivot screw passing through the presser-foot closely adjacent one of the lateral edges determining the length of the work-engaging surface and through an extension of the Presser-foot guide-plate suitably secured to the presseh gaging surface moves to such a slight extent during adjustment of the angle of the presser-foot as to be negligible, but the position of the presser-foot is nevertheless positively determined without any ill effects due to lost motion.

In the accompanying drawings, Figure 1 is a front end elevation of a skiving ma chine embodying the present improvement, omitting features of construction unessential to an understanding of the invention.

' Fig. 2 is a disassembled perspective view of the presser-bar and the parts carried there by. Fig. 3 is an end elevation of the presser-foot as viewed from the right in Fig. 1.

Referring to the drawings, the skiving machine consists of a base 1 from which rises the overhanging arm 2 terminating in the head 3. Mounted for vertical movement in the head 3 is the presser-bar provided with a reduced threaded portion 5 engaged by the adjusting nut 6 held against vertical movement and projecting through a slot 7 formed in the head 3. At its lower end the Presser-bar carries a bracket 8 partially cut away to provide clearance for the presserfoot or member 9 formed with a curved work-engaging surface 10. The presser-foot is confined to oscillatory movements by a guide-plate 11, secured by screws as 12 to the presser-foot bracket and formed with an apertured extension or ear 13. A pivot screw 14 passing through the aperture in the car 13 enters a threaded aperture 15 formed in the presser-foot at a point closely adjacent a lateral edge 16 of the work-engaging surface.

The upper surface of the presser-foot is provided with a segmental toothed rack 17 engaged by the teeth of a pinion 18 positioned in an aperture 19 provided for the purpose in the presser-bar bracket. The pinion 18 is carried by a short shaft 20 secured as by means of a pin 21 to a tubular adjusting screw 22 held in by a lock-nut 23.

Cooperating with the presser-foot is a feedingelement or- Wheel 2st having a curved peripheral surface corresponding substantially to the curvature of the circular skiving knife 25 with Which the curved Work-engaging surface of the presser-foot also substantially corresponds. The presserfoot is adjustable in a plane substantially at right angles to the direction of feed and, it will be observed, about an axis closely adjacent the periphery of the skiving knife.

The provision of a positive axis closely adjacent one of the lateral edges of the Work-engaging surface of the presser-foot and upon Which the resser-foot may be adjusted in the manner described permits considerable movement of the opposite lateral edge thereof to alter the skiving angle With but small movement of the edge 16. Inasmuch as the degree of adjustment required is very small, usually not exceeding three teeth of the segment, any movement of the edge 16 is negligible.

Having thus set forth the nature of the invention, What I claim herein isadjusted position 1. A skiving machine presser-foot comprising a presser member capable of oscillatory movements about a bearing located Within the free-edges of said member and closely adjacent the intersection of one of said edges and the free edge comprising the work engaging surface, means for angularly adjusting said presserefoot about said hearing, and means for positively securing said presser member against accidental oscillation.

2. In a 'skiving machine a presser-bar, a bracket sustained by said presser-bar; a presser-foot, a presser-foot guide-plate secured to said bracket and pivotally sustaining said presser-foot, and means for adjusting said presser-foot for different angles of skiving. j I

3. In a skiving machine, a presser-bar, a bracket sustained by said presser-bar, a

presser-foot, a presser-foot guide-plate secured to said bracket and pivotally sustaining said presser-foot, and meansincluding a segmental rack and a pinlon for ad usting said presser-foot for different angles of skiving.

In testimony whereof; I have signed my name to this specification.

WILLIAM P. OROCKETT. 

